Step-screen for pulp-chips



No. 62|,402. Patented Mar. 2|, I899.

' W. A. FANNON.

STEP SCREEN FOR PULP CHIPS.

(Application filed Oct. 11, 1897.)

(No Model.)

2 SheetsSheet I,

Witnesses.

M Inventor. I

W' M 5; 05M;

Attorneys m: Nomus PETERS ca. PHOTO-HTML WASHINGTON. n. c,

No. 62!,402. Patented Mar. 2|, I899.

W., A. FANNUN.

STEP SCREEN FOB PULP CHIPS.

' (Applicstion filed Oct. 11, 1897.)

(No Model.) I 2 Sheets-Sheet 2 "Witnesses; Inv entor.

o Q /ZWMM 5W flaw 9M m: N mms Firms :0. PHOTCLLIIHOH WAISJINGTDN, a. c.

rrn "ra'rns \VILLIAM ALSOP FANNON, OF APPLETON, WISCONSIN.

STEP-SCREEN .FOR PU LP-CHIPS.

SPECIFICATION formingpart of Letters Patent No. 621,402, dated March 21,1899.

Application filed October 11, 1897. Serial No. 654,860. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM ALsoP FAN- NoN, a citizen of the UnitedStates, residing at Appleton, in the county of Outagamie and State of\Visconsin, have invented new and useful Improvements in Step Screensfor Pulp-Chips, of which the following is a specification.

My invention relates to improvements in step-screens for pulp-chips.

It is well known among manufacturers of paper from wood-pulp. that theappearance and purity of the paper depend largely upon the quality ofthe pulp-chips and their freedom from bark and other foreign matter. Itis also well known that it is exceedingly difficult to remove the'fragments of bark from the pulp-chips owing totheir tendency to lodge inthe crevices of the chips.

The objects of my invention are,first,to provide a device in which thechips will be turned over at intervals and thoroughly shaken up todislodge and remove the bark fragments, and, second, to provide forsorting the chips, whereby the smaller chips, which contain not only thefragments of bark, but also those of knots and bits of decayed wood, maybe separated and graded for the manufacture of various qualities ofpaper.

In the following description reference is had to the accompanyingdrawings, in which- Figure l is an elevation showing the arrangement ofthe screens between the supporting-walls. Fig. 2 is a section view drawnon line as x of Fig. 1. Fig. 3 is aviewsimilar to that shown in Fig. 1,illustrating a further in odification of my invention. Fig. etis a sideview of the same with. one I of the inclosing walls removed to show theinterior.

Like parts are identified by the same reference-letters throughout theseveral views.

A zigzag chute is formed between the inclosing walls A A by means of theinclined platforms B and screens 0, the screens being located to formthe under side of each section of the chute and the platform the upperside of such sections. The screens are preferably made removable, beingsupported between the walls A A by cleats D and shoulders E, the latterbeing arranged to project from the screen-frames in a position to engagethe walls A A. With this construction of the chute it is evident thatthe material which passes through any one of the screens 0 drops uponthe upper surface of the platform B of the next section beneath andslides down into a trough F, which is laterally inclined, so as todischarge the material at one side of the chutes.

By using screens of small mesh in the upper portion of the chute andincreasing the size of the mesh in the successive screens below it isevident that material escaping therethrough will be graded in size andalso in quality, as the refuse matter is usually small in size, andtherefore escapes through the screens of small mesh in the upper portionof the chute. At the bottom of the chute the remaining material, whichrepresents the best quality and usually the principal portion of thepulp-chips, is dropped upon a conveyor G and transported to the point ofuse.

The material is fed into the chute through a hopper H. As it drops fromone screen to another it is turned over and the resiliency of thescreens causes it to bound violently, thus shaking out the particles ofbark and other refuse from the crevices.

In order to thoroughly shake the chips'while passing through the chute,I support the chute upon the levers I, the latter being pivoted at J andarranged to engage studs K, projecting from the chute-walls. The leversare actuated by a shaft L, provided with arms M, which are adapted tosuccessively lift the end of the lever to raise the chute and permit itto drop to its original position as the actuating arm escapes past theend of the lever.

In Figs. 3 and 4 I have illustrated a further means for shaking up thechips, which is adapted to be used in addition to the means shown inFigs. 1 and 2. Rotary screen-drums R are interposed between the lowerends of the screens 0 and the upper ends of the succeeding platforms B,the efiect of the screens being to throw the chips from the upperscreens to those next below and at the same time insure their beingturned and shaken. Motion is communicated to the drums from the sourceof power through a sprocket-chain S and pinion T. The platforms areprovided with shields U, adapted to prevent the escape of the chipsbetween them and the drums. The dirt or other foreign matter ispermitted to escape through the drums, as well as through the screens 0.This form of construction is especially recommended where the quality ofthe chips is poor or where extra cleaning is required, as in this devicethe .chips may be shaken up with any desired violence while passingthrough the chute.

\Vhile my invention is peculiarly adapted for cleaning and separatingpulp-chips, it is evident that it may also be used for screen ing coaland for other similar purposes.

What I claim as new, and desire to secure by Letters Patent, is-

1. The combination with supporting side walls, of a chute formed of aplurality of alternating screens and platforms, screen-covered drumsarranged between the successive screens and the succeeding platforms, alever supporting the lower end of the chute, means forintermittinglyraisin g said leverand chute, and permiting the same to drop to theiroriginal position, and meansfor impartinga rotary movement to said drumswhereby the pulpchips are shaken with the movement of the chutes andturned with the independent movement of the drums, substantially for thepurpose set forth.

2. The combination with supporting side walls, of a chute formed of aplurality of screens and platforms, arranged in zigzag series betweenthe side Walls, a lever support ing the lower end of the chute,and meansfor intermittingly raising said lever and chute and permitting the sameto drop to its original position, substantially for the purpose setforth.

3. The combination with supporting side walls, of a chute, formed of aplurality of screens and platforms, arranged in zigzag series betweensaid side walls, of a lever supporting the lower end of the chute, andashaft provided with arms adapted to intermittingly raise the ends ofthe lever and permit the same to drop to its original position,substantially for the purpose set forth.

4. The combination with supporting side walls, of a chute formed of aplurality of 'alternating screens and platforms, screen-covered drumsarranged between the respective screens and the succeeding platforms,and means for communicating motion to the drums, substantially for thepurpose set forth.

In testimony whereof I affix my signature in the presence of twowitnesses.

XVILLIAM ALSOP FANNON. lVitnesses:

JOHN NELLIE, JOHN DICK.

